Controlling Vehicle-to-Vehicle Communication Using a Distribution Scheme

ABSTRACT

A method, a node, an entity and a computer program for controlling vehicle-to-vehicle communication is described. The vehicle-to-vehicle communication is performable using a first radio technology for performing the vehicle-to-vehicle communication and a second radio technology for accessing a cellular network. The method comprises determining ( 234 ) a distribution scheme for distributing a transmission of vehicle-to-vehicle communication messages among the first radio technology and the second radio technology, and, in accordance with the determined distribution scheme, a vehicle-to-vehicle communication device ( 116   a,    116   b ) controlling ( 238, 240 ) the transmission of the vehicle-to-vehicle communication messages. Therefore the vehicle-to-vehicle communication can be easily and efficiently controlled and the accordingly controlled vehicle-to-vehicle communication can be performed in an easy, efficient, cost-effective and reliable way.

TECHNICAL FIELD

The present invention relates to controlling vehicle-to-vehiclecommunication and to corresponding methods, devices, nodes, entities,computer programs and a corresponding communication system.

BACKGROUND

In vehicular transport and traffic management, intelligent transportsystem (ITS) applications are used for supporting drivers. Thereby,traffic safety can be improved by providing the drivers with informationallowing for making smarter decisions in the traffic. Such ITSapplications may involve transmitting information between differentvehicles, for example in the form of a Cooperative Awareness Message(CAM). The information may be used for providing a warning or guidanceto the driver, for example in the form of an emergency vehicle warning,an intersection collision warning, a slow vehicle warning, or amotorcycle approaching indication. The information may be transmittedusing a radio technology for vehicle-to-vehicle (V2V) communication, forexample as specified by an IEEE 802.11p standard, also referred to asWireless Access in Vehicular Environments (WAVE). According to the IEEE802.11p standard, a wireless ad-hoc network may be formed betweendifferent vehicles.

CAMs are messages which are usually periodically broadcasted by avehicle to inform further vehicles in the surrounding about the currentstatus of the transmitting vehicle. CAMs may, for example, be used fortransmitting information such as the current geographical position,speed, and/or basic attributes of the vehicle. A vehicle may receive oneor more CAMs from other vehicles and may utilize the informationprovided in the one or more CAMs for supporting its driver, for exampleby providing a warning or other guidance.

It is also envisioned to use a radio technology usually being used foraccessing a cellular network, for example Long-Term Evolution (LTE) orHigh-Speed Packet Access (HSPA), in order to transmit the abovedescribed information.

SUMMARY

It is an object of the present invention to provide measures with whicha V2V communication can be easily and efficiently controlled and theaccordingly controlled V2V communication can be performed in an easy,efficient, cost-effective and reliable way. It is also an object of thepresent invention to provide corresponding methods, devices, nodes,entities, computer programs and a corresponding communication system.

Methods, a V2V communication device, a node, an entity, a communicationsystem, and computer programs according to the independent claims areprovided.

According to an exemplary aspect of the invention, a method forcontrolling V2V communication is provided. The V2V communication isperformable using a first radio technology for performing the V2Vcommunication and a second radio technology for accessing a cellularnetwork. The method comprises determining a distribution scheme fordistributing a transmission of V2V communication messages among thefirst radio technology and the second radio technology, and, inaccordance with the determined distribution scheme, a V2V communicationdevice controlling the transmission of the V2V communication messages.

According to another exemplary aspect of the invention, a method forcontrolling V2V communication is provided. The V2V communication isperformable using a first radio technology for performing the V2Vcommunication and a second radio technology for accessing a cellularnetwork. The method is performed by a V2V communication device andcomprises controlling a transmission of V2V communication messages inaccordance with a determined distribution scheme for distributing atransmission of the V2V messages among the first radio technology andthe second radio technology.

According to another exemplary aspect of the invention, a V2Vcommunication device for controlling V2V communication is provided. TheV2V communication is performable using a first radio technology forperforming the V2V communication and a second radio technology foraccessing a cellular network. The V2V communication device is adapted tocontrol a transmission of V2V communication messages in accordance witha determined distribution scheme for distributing a transmission of theV2V messages among the first radio technology and the second radiotechnology.

According to another exemplary aspect of the invention, a method usablein association with controlling V2V communication is provided. The V2Vcommunication is performable using a first radio technology forperforming the V2V communication and a second radio technology foraccessing a cellular network. The method is performed by a node of thecellular network and comprises determining a distribution scheme fordistributing a transmission of V2V communication messages among thefirst radio technology and the second radio technology. The methodcomprises transmitting the determined distribution scheme to a V2Vcommunication device.

According to another exemplary aspect of the invention, a node for acellular network and being usable in association with controlling V2Vcommunication is provided. The V2V communication is performable using afirst radio technology for performing the V2V communication and a secondradio technology for accessing the cellular network. The node is adaptedto determine a distribution scheme for distributing a transmission ofV2V communication messages among the first radio technology and thesecond radio technology, and to transmit the determined distributionscheme to a V2V communication device.

According to another exemplary aspect of the invention, a method usablein association with controlling V2V communication is provided. The V2Vcommunication is performable using a first radio technology forperforming the V2V communication and a second radio technology foraccessing a cellular network. The method is performed by an entity andcomprises transmitting information impacting a determination of adistribution scheme for distributing a transmission of V2V communicationmessages among the first radio technology and the second radiotechnology to a further entity, particularly a V2V communication deviceadapted to determine the distribution scheme or a node of the cellularnetwork adapted to determine the distribution scheme.

According to another exemplary aspect of the invention, an entity beingusable in association with controlling V2V communication is provided.The V2V communication is performable using a first radio technology forperforming the V2V communication and a second radio technology foraccessing the cellular network. The entity is adapted to transmitinformation impacting a determination of a distribution scheme fordistributing a transmission of V2V communication messages among thefirst radio technology and the second radio technology to a furtherentity, particularly a V2V communication device adapted to determine thedistribution scheme or a node of the cellular network adapted todetermine the distribution scheme.

According to another exemplary aspect of the invention, a communicationsystem for controlling a vehicle to vehicle communication is provided.The communication system comprises a V2V communication device describedabove, and at least one of a node described above and an entitydescribed above.

According to another exemplary aspect of the invention, a computerprogram is provided. The computer program, when being executed by atleast one processor, causes a method described above to be performed.

According to another exemplary aspect of the invention, a computerprogram product is provided. The computer program product comprisesprogram code to be executed by at least one processor. Thereby a methoddescribed above is caused to be performed.

Further embodiments are described in the dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram schematically illustrating a V2V communicationscenario in which concepts according to embodiments of the invention areapplied.

FIG. 2 is a signaling diagram schematically illustrating a method forcontrolling a V2V communication according to an embodiment of theinvention.

FIG. 3 is a signaling diagram schematically illustrating a method forcontrolling a V2V communication according to an embodiment of theinvention.

FIG. 4 is a block diagram schematically illustrating a V2V communicationdevice according to an embodiment of the invention.

FIG. 5 is a block diagram schematically illustrating a node for acellular network and being usable in association with controlling V2Vcommunication according to an embodiment of the invention.

FIG. 6 is a block diagram schematically illustrating an entity usable inassociation with controlling a V2V communication according to anembodiment of the invention.

DETAILED DESCRIPTION OF EMBODIMENTS

It is noted that similar or identical elements or steps in the Figuresare referenced by the same reference numeral or by reference numeralswhich are only different within the first digit. Dashed elements in theFigures denote optional features.

In the following, concepts according to the exemplary aspects of theinvention will be explained in more detail. These concepts relate tocontrolling V2V communication between V2V communication devices. The V2Vcommunication may be used to implement a transport system application,for example an ITS application, based on the transmission of V2Vcommunication messages, for example CAMs, between the V2V communicationdevices. In this respect, a transport system may denote a systemutilized in the area of transportation, for example passenger and/orcargo transportation. Such a system might be different from a transportlayer of a layered based communication model of a communication network,for example a cellular network. The transport system application mayprovide respective functionalities in the transport system.

According to the concepts, the V2V communication can be performed by aV2V communication device using a first radio technology for performingthe V2V communication and a second radio technology for accessing acellular network. For example, the first and second radio technologiesare different from one another. The first radio technology may have asmaller transmission area in which V2V communications may betransmittable compared to a transmission area in which the V2Vcommunication messages may be transmittable via the second radiotechnology.

The first radio technology may be embodied, for example, as an ad-hocWireless Local Area Network (WLAN) according to IEEE 802.11p or LTEdevice-to-device (D2D). A corresponding transmission area of the CAMsmay be up to few hundred meters. Further, a typically used transmissionfrequency of the CAMs may be about 10 Hertz (Hz). The second radiotechnology may be defined as specified by Third Generation PartnershipProject (3GPP) or by 3GPP2. The cellular network may implement one ormore radio technologies, such as Global System for Mobile Communication(GSM), Universal Terrestrial Mobile Telecommunication System (UMTS) orWideband Code Division Multiple Access (CDAM), CDMA2000, WiMaX, 3GPPService Architecture Evolution (SAE)/LTE, and/or 3GPP LTE-Advanced.

Hence, according to the exemplary aspects of the invention, a hybrid V2Vcommunication device may be provided, which may operate in accordancewith the first and second radio technologies. Resources for transmittingV2V communication messages, for example the above-mentioned CAMs, may beallocated in accordance with a determined distribution scheme specifyinga distribution of the V2V messages to be sent via the first and secondradio technologies. The determined distribution scheme may represent astatic distribution scheme, hence may be once determined and applied infuture by the V2V communication device without further changes to thedetermined distribution scheme. Alternatively, the determineddistribution scheme may be dynamically determined, in order to adapt theV2V communication of the V2V communication device to changes in thesurrounding of the V2V communication device. In this respect, the lattermentioned changes may form constraints for the V2V communication.

Therefore the V2V communication of the V2V communication device may beeasily and efficiently controlled by utilizing the determineddistribution scheme in the V2V communication device. In particular, theV2V communication device might not need to determine on a per V2Vcommunication message basis the radio technology via which the V2Vcommunication message should be sent considering current constraintspresented by the cellular network and/or the V2V communication device.Further, a single equipment, namely the V2V communication device, may beutilized for communication both via the first radio technology and thesecond radio technology.

An enhanced V2V communication may be enabled by employing beneficialselected characteristics of the first and second radio technologies,such as reliability, availability, costs and efficiency while, at thesame time, at least reducing or even avoiding and/or mutuallycompensating drawbacks of the first and second communicationtechnologies. In particular, such a type of V2V communication may not beachieved by using only one of the first and second radio technologies.In this respect, by utilizing the second radio technology for the V2Vcommunication, the second radio technology may take a fraction of V2Vcommunication messages not being transmittable via the first radiotechnology, for example in a case in which the traffic capacity via thefirst radio technology may be consumed.

For example, the first radio technology may offer transmission of a hightraffic load by utilizing a complete frequency range dedicated for theV2V communication, for example a 5.9 GHz band used by the IEEE 802.11pstandard. On the other hand, a transmission reliability of the firstradio technology for the V2V communication messages may depend on afrequency of the transmitted V2V communication message and/or may be lowowing to not existing mechanisms for ensuring successful transmission ofthe V2V communication messages, for example in the event of packet loss,connectivity loss, packet collision, transmission error and/or delay inthe transmitting V2V communication device.

For example, the transmission via the second radio technology may beefficient and reliable, and the second radio technology may be anubiquitously available technique. Further, the transmission via thesecond radio technology may be cost-effectively utilized, sincetransmission capabilities of a vehicle in or on which the V2Vcommunication device can be mounted may be present for non V2Vcommunication purposes and can be reused for the V2V communication withlow extra costs. On the other hand, the second radio technology mightnot support a required high traffic load for the V2V communication,since a revenue for utilizing the second radio technology for the V2Vcommunication may be lower compared to an utilization of the secondradio technology for conventional data traffic between a terminal andthe cellular network and/or a transmission capacity via the second radiotechnology may be limited depending on time and/or location.

Next, further embodiments of the method for controlling V2Vcommunication may be explained. These embodiments also apply to theother methods, the V2V communication device, the node, the entity, thecommunication system, and the computer programs.

The distribution scheme may represent a configuration for the V2Vcommunication device which may specify a filtering of V2V communicationmessages according to a radio interface to be used for a transmissionthereof and may accordingly distribute the V2V communication messagestowards a first radio interface of the V2V communication deviceoperating in accordance with the first radio technology and towards asecond radio interface of the V2V communication device operating inaccordance with the second radio technology. The V2V communicationmessages may be, for example, generated by the transport systemapplication residing in the V2V communication device.

The determined distribution scheme may specify a transmission rate inaccordance with which the V2V communication messages may be to betransmitted via the first and/or second radio technologies. In thisrespect, the transmission rate may relate to a fraction of V2Vcommunication messages among a specified number of consecutivelytransmitted V2V communication messages which may be to be sent via thefirst and/or second radio technologies. A sequence of the V2Vcommunication messages transmitted via the first radio technology andtransmitted via the second radio technology might be not defined by thetransmission rate. In particular, a particular specified transmissionrate of V2V messages to be transmitted via one radio technology mayaccordingly define a transmission rate of the other V2V messages to betransmitted via the other radio technology. For example, a transmissionrate via the first radio technology may correspond to 9/10, i.e. 9 V2Vcommunication messages out of a group of 10 V2V communication messagesmay have to be sent via the first radio technology with a sequence ofthe V2V communication messages being not specified. A correspondingtransmission rate via the second radio technology may accordingly be1/10. This measure may increase a reliability of a successfultransmission of the V2V communication messages and meanwhilecompensating a load on both radio technologies. In particular, asuitable selection of the transmission rate may enable to transmit asmuch V2V communication messages as possible via the first radiotechnology, in order to utilize the beneficial characteristics of thefirst radio technology pertaining to costs, traffic capacity, and a timeand/or location independent transmission possibility.

The determined distribution scheme may specify a transmission frequencyin accordance with which V2V communication messages may be to betransmitted via the first and/or second radio technologies. In thisrespect, a transmission frequency of V2V communication messages maycorrespond to a defined number of the V2V communication messages to betransmitted and to a time occurrence of the V2V communication messagesto be transmitted in a group of consecutively transmitted V2Vcommunication messages to be transmitted. As explained above, atransmission frequency of a V2V communication via one radio technologymay accordingly specify a transmission frequency of V2V communicationmessages via the other radio technology, particularly assuming a totaltransmission frequency of the V2V communication messages via the firstand second radio technologies may be known. The total transmissionfrequency may be defined by a potentially usable maximum transmissionfrequency of the V2V communication messages via the first radiotechnology. For example, a transmission frequency of 1 Hz via the firstradio technology may specify that 1 V2V communication message of a groupof consecutively transmitted V2V communication messages may be to betransmitted per second via the dedicated radio technology. Under theassumption that a total number of V2V messages per second may be known,a transmission frequency of the V2V messages via the second radiotechnology can be accordingly derived. Therefore, as explained above, areliability of a successful transmission of the V2V communicationmessages may be enabled while decreasing load on both radiotechnologies. In particular, a suitable selection of the transmissionfrequency may enable to transmit as much V2V communication messages aspossible via the first radio technology, in order to utilize thecharacteristics of the first radio technology pertaining to costs,traffic capacity, and a time and/or location independent transmissionpossibility.

The determined distribution scheme may specify that all V2Vcommunication messages may be to be transmitted via the first radiotechnology and a subset of the V2V communication messages may be to betransmitted via the second radio technology. This measure may decreaseload on the second radio technology and reduce costs for thetransmission of the V2V communication messages despite utilizing thesecond radio technology, while ensuring that the subset of V2Vcommunication messages may be expected to be successfully received by arecipient because of the transmission thereof via the second radiotechnology.

The determined distribution scheme may specify that a V2V communicationmessage having a certain priority may be to be transmitted via thesecond radio technology, and a V2V communication message having apriority different from the certain priority may be to be transmittedvia the first radio technology. In particular, the certain priority maybe higher than the different priority. Therefore, transmissionreliability of the V2V communication messages and a successful receptionthereof may be enhanced, while still providing the V2V communication atlow costs.

The priority of a V2V communication message may be defined based on acontent of the V2V communication message and/or a type of the V2Vcommunication message. A content of the V2V communication message mayrelate, for example amongst others, to a current geographical positionof the V2V communication device, a speed of the V2V communicationdevice, and/or basic attributes of a vehicle in or on which the V2Vcommunication device may be mounted. Such an attribute may relate to,for example, to an identification of the corresponding vehicle, a usageof the corresponding vehicle, a technical specification of thecorresponding vehicle such as length, engine power, brand of thecorresponding vehicle or the like. A type of a V2V communication messagemay relate to a purpose of a transmission of the V2V communicationmessage. Such a purpose may be an accident warning, an emergency vehicleapproaching, or the like. For example, a V2V communication messageindicating an accident warning may have a higher priority than normalV2V communication messages used to disseminate, for example, thelocation of the vehicles in or on which the V2V communication device maybe mounted. Therefore the V2V communication messages can be beneficiallytransmitted in accordance with their inherently defined importance. Thestep of transmitting the V2V communication messages may comprisedetermining the priority of the respective V2V communication messages tobe transmitted and transmitting the V2V communication messages inaccordance with the distribution scheme.

The distribution scheme may be determined for a certain coverage area ofthe second radio technology. For example, the coverage area maycorrespond to one or more cells served by an access node operating inaccordance with the second radio technology. In particular, twodistribution schemes may be determined for mutually exclusive coverageareas. In this case, the two distribution schemes may be different ormay be identical to one another. Limiting a distribution scheme to aparticular geographical area may allow tailoring the V2V communicationto network- and/or device-based constraints in this geographical areasuch that the efficiency, costs, reliability and availability of the V2Vcommunication can be adapted to these constraints.

The distribution scheme may be determined by a V2V communication deviceor by a node of the cellular network. The V2V communication device maythe V2V communication device according to the exemplary aspects, whichV2V communication device may control its transmission of the V2Vcommunication messages in accordance with the distribution scheme, ormay be a further different V2V communication device. The node may be anaccess node operating in accordance with the second radio technology ora transport system server which may be particularly located in a corenetwork of the cellular network. In the first configuration, adetermination of the distribution scheme by a V2V communication devicemay allow for controlling the V2V communication even in a case ofconnectivity failure towards the cellular network via the second radioaccess technology. Further, network resources associated withdistributing the distribution scheme over a radio link and processingcomplexity of the V2V communication device not determining thedistribution scheme may be low. In the second configuration, thedetermination of the distribution scheme on the network side may providea central network entity to which multiple V2V communication devices maybe equally connectable in a particular coverage area of the second radiotechnology for receiving the determined distribution scheme. Processingcomplexity of the V2V communication devices may be low. A determinationof the distribution scheme by the access node may provide an efficientmeasure in that the access node may be involved in the transmission ofthe V2V communication messages and may use inherent information relatedto an actual data transmission via the second radio technology.Determining the distribution scheme by a transport system server outsideof a coverage area of the second radio technology may enable to reusethe same network node for determining distribution schemes associatedwith different second radio technologies.

The method may further comprise transmitting the determined distributionscheme to the V2V communication device in a broadcast transmission or inan unicast transmission. In the first configuration, the distributionscheme may be beneficially transmitted at the same time instance to allV2V communication devices listening to the broadcast transmission in aneasy and efficient way. In the second configuration, network resourcescan be saved, since a particular V2V communication device can beprecisely addressed, for example in the event of a regular update of thedistribution scheme for a coverage area of an access node which may besmaller than the total coverage area of the access node.

In particular, in a case in which the distribution scheme may bedetermined by the V2V communication device or the further V2Vcommunication device, the distribution scheme may be transmitted via thefirst radio technology. In such a case, the distribution scheme may beincluded in a regularly transmitted V2V communication message which maybe particularly broadcasted. Alternatively or additionally, thedistribution scheme may be also transmitted, particularly broadcasted,in a separate V2V communication message upon determining thedistribution scheme. Alternatively or additionally, the distributionscheme may be transmitted via the second radio technology to the node ofthe cellular network which may then transmit the distribution scheme viathe second radio technology, for example in a broadcast transmission orin an unicast transmission, to respective receiving V2V communicationdevices.

In particular, in a case in which the distribution scheme may bedetermined by the access node, the distribution scheme may betransmitted via the second radio technology, for example in a broadcasttransmission or in an unicast transmission to a respective receiving V2Vcommunication device or respective receiving V2V communication devices.

In particular, in a case in which the distribution scheme may bedetermined by the transport system server, the distribution scheme maybe transmitted via the second radio technology, for example in abroadcast transmission or in an unicast transmission to respectivereceiving V2V communication devices. In a case in which the transportsystem server may be located in the core network, the distributionscheme may be firstly transmitted, for example in an unicasttransmission, to a respective access node operating in accordance withthe second radio technology which then further transmits thedistribution scheme via the second radio technology, as beforehandexplained.

The determined distribution scheme may be transmitted in a handovercommand to the V2V communication device when the V2V communicationdevice may enter a coverage area of the second radio technology forwhich the distribution scheme may have been determined. This measure mayallow for communicating the distribution scheme in an efficient way andalso only upon necessity.

The distribution scheme may be determined based on information relatingto a density of entities comprising transmission capabilities fortransmission via the first radio technology in a certain coverage areaof the second radio technology at a given time. These entities may beV2V communication devices and/or fixed infrastructure nodes operating inaccordance with the first radio technology. In this respect, the V2Vcommunication devices being enabled for V2V communication via the firstradio technology may form an ad-hoc network for the V2V communication.The fixed infrastructure nodes may offer an increase of the transmissionarea for the V2V communication messages to be transmitted via the firstradio technology by forwarding received V2V communication messages tofurther recipients. For example, the distribution scheme may specify alarger fraction of the V2V communication messages to be sent via thefirst radio technology, if the density of the entities may besufficiently high, as the latter may cause a sufficient goodavailability of the first radio technology for the V2V communication andthus a reliable transmission of the V2V communication messages via thefirst radio technology.

In particular, one or more V2V communication devices and/or one or moreinfrastructure nodes, particularly each V2V communication device and/orinfrastructure node, may communicate its own capability to another V2Vcommunication device or to a node of the cellular network for thedetermination of the distribution scheme. The respective information maybe transmitted in a separate message via the second radio technologyand/or may be included in a V2V communication message, for example, asseparate identifier. Additionally or alternatively, the node of thecellular network, particularly the access node or the transport systemserver, may monitor the density of the entities and may provide thecorresponding information to the V2V communication device determiningthe distribution scheme. Additionally or alternatively, a sensor locatedin the certain coverage area may provide the respective information bymonitoring the V2V communication traffic and optionally by deriving anumber or density of the entities in the certain coverage area. In thisrespect, a sensor may represent a device adapted to monitor respectiveinformation and optionally to determine a parameter value based on themonitored information. Such a sensor may be temporarily or permanentlyinstalled in the certain coverage area, for example in a constructionarea or at a tunnel entrance, and may monitor the respective number ofdevices.

In particular, in order to determine its own transmission capability viathe first radio technology, the respective V2V communication device maydetermine a kind of one or more radio interfaces of the V2Vcommunication device. In particular, the V2V communication device maydetermine that the V2V communication device may comprise transmissioncapabilities for transmission via the first radio technology, if atleast one of the one or more radio interfaces of the V2V communicationdevice may operate in accordance with the first radio technology, andmay determine that the V2V communication device may be free of suchtransmission capabilities else.

Additionally or alternatively, the distribution scheme is determinedbased on information relating to an average connectivity via the firstradio technology in a certain coverage area of the second radiotechnology at a given time. In particular, the coverage area and/or thegiven time for which the density of entities may be defined may bedifferent or identical to the coverage area and/or the given time,respectively, for which the average connectivity may be defined. Thedensity of entities comprising transmission capabilities fortransmission via the first radio technology may contribute to a level ofthe average connectivity. Further, information such as a traffic loadvia the first radio technology may also impact the average connectivity.As mentioned above, the distribution scheme may specify a largerfraction of the V2V communication messages to be sent via the firstradio technology, if the average connectivity via the first radiotechnology may be high.

Additionally or alternatively, the distribution scheme may be determinedbased on information relating to an available transmission capacity tobe, particularly potentially, usable for the V2V communication via thesecond radio technology in a certain coverage area of the second radiotechnology at a given time. In particular, the coverage area and/or thegiven time for which the density of entities and/or the averageconnectivity may be defined may be different or identical to thecoverage area and/or the given time, respectively, for which theavailable transmission capacity may be defined. The availabletransmission capacity may impact, for example, the transmission rateand/or the transmission frequency with which the V2V communicationmessages can be transmitted via the second radio technology. Inparticular, the available transmission capacity may be determined by theaccess node. For example, the distribution scheme can specify a highernumber of the V2V communication messages to be transmitted via thesecond radio technology, if the available network capacity for the V2Vcommunication can be sufficiently high. The accordingly determineddistribution scheme may specify that as many V2V communication messagesas possible can be transmitted via the second radio technology.

Additionally or alternatively, the distribution scheme may be determinedbased on information relating to a priority and/or a type of a V2Vcommunication message to be transmitted. In such a case, the prioritymay be defined by a transport system application, for example residingin the V2V communication device, or by a transport system function, forexample residing in the transport system server or in the access nodewhich may particularly implement such a transport system function. Inthis respect, the transport system function may represent a network sidecounterpart functionality for the transport system application in atransport system implemented in the cellular network. Hence, the V2Vcommunication device may represent a client to a respective server ofthe transport system, which server may implement the transport systemfunction. The priority of a V2V communication message may impact, forexample, the selection of the subset of V2V communication messages to betransmitted via the second radio technology, the transmission rateand/or the transmission frequency with which the V2V communicationmessage may be to be transmitted via the second radio technology and/orthe priority level based transmission of the V2V communication messages.A sending of the V2V communication message having a high priority viathe second radio technology may enable a reliable transmission and asuccessful reception thereof.

Additionally or alternatively, the distribution scheme may be determinedbased on information relating to a required transmission area in which aV2V communication message may have to be transmitted. This informationmay be provided by the transport system application, for exampleresiding in the V2V communication device, or the transport systemfunction, for example residing the access node or the transport systemserver. For example, the higher the required transmission area fortransmitting the V2V communication message may be, the more likely thedistribution scheme may specify that the V2V communication message or alarger fraction of multiple V2V communication messages may have to betransmitted via the second radio technology, optionally in addition to aduplication of the V2V communication message via the first and secondradio technology. On the contrary, a low required transmission area maylead to a distribution scheme specifying a transmission of the V2Vcommunication message or a larger fraction of the multiple V2Vcommunication messages via the first radio technology.

In particular, an accuracy of the determined distribution scheme withrespect to constraints in a surrounding of the V2V communication devicemay be high, since one or more of the above described information may beused as input for the determination of the distribution scheme.

At least one of the above information may be provided by an entity,particularly the V2V communication device according to the exemplaryaspects, a further V2V communication device, by the node or by thesensor. In particular, the information relating to the priority and/orthe type of the V2V communication message and/or the requiredtransmission area may be provided by the transport system application orfunction of a respective entity.

In particular, the step of providing may comprise providing therespective information for example from a transport system applicationor function to at least one processor of the respective entity.Additionally or alternatively, the step of providing may comprisemonitoring the at least one information for example during a definedtime interval or in a continuous way. Additionally or alternatively, thestep of providing may comprise transmitting the respective informationvia the first radio technology. Additionally or alternatively, the stepof providing may comprise transmitting the respective information overthe cellular network via the second radio technology. Additionally oralternatively, a similar type and/or a different type of information maybe provided by one entity or by multiple entities as input for the stepof determining.

In particular, the V2V communication device may transmit, for examplebroadcast or use an unicast transmission, the information to another V2Vcommunication device via the first radio technology. Additionally oralternatively, the V2V communication device may transmit the informationto the access node via the second radio technology, and the access nodemay forward, for example broadcast or using an unicast transmission, theinformation to one or more V2V communication devices.

In particular, the access node may transmit the information via thesecond radio technology to the V2V communication device, for exampleusing an broadcast or unicast transmission.

In particular, the transport system server may transmit the informationvia the second radio technology to the V2V communication device, forexample using an broadcast or unicast transmission. In a case in whichtransport system server may be located in the core network, thetransport system server may firstly send the respective information toan access node of the cellular network. The latter may also apply forthe transmission of the information to the access node determining thedistribution scheme.

In particular, the sensor may transmit the information via the firstradio technology or via the second radio technology.

Next, further exemplary embodiments of the V2V communication device willbe explained. However, these embodiments also apply to the methods, thenode, the entity, the communication system and the computer programs.

The V2V communication device may be adapted to perform a methoddescribed above. To this end, the V2V communication device may comprisecorresponding program code stored, for example, in a memory of the V2Vcommunication device and/or corresponding hardware structure, forexample at least one radio interface, one or more processors, and/or amemory. The V2V communication device may also implement a transportsystem application.

The V2V communication device may be comprised in a vehicle for passengertransport and/or cargo transport.

Next, further exemplary embodiments of the node will be explained.However, these embodiments also apply to the methods, the V2Vcommunication device, the entity, the communication system and thecomputer programs.

The node may be adapted to perform a method described above. To thisend, the node may comprise corresponding program code stored, forexample, in a memory of the node and/or corresponding hardwarestructure, for example on or more suitable interfaces, one or moreprocessors, and/or a memory. The node may implement a transport systemfunction, as explained above.

The node may be adapted as an access node operating in accordance withthe second radio technology or a transport system server, particularlyan ITS server. The access node may be adapted to manage radio resourceallocation for a transmission via the second radio technology, hence maybe adapted as a radio resource management node of an access network, forexample, an eNodeB or a Radio Network Controller. The access node mayalso implement a transport system function. The transport system servermay be part of a cloud or may form an individual separate networkelement.

Next, further exemplary embodiments of the entity will be explained.However, these embodiments also apply to the methods, the V2Vcommunication device, the node, the communication system and thecomputer programs.

The entity may be part of the cellular network and may be accordinglyembodied as an access node operating in accordance with the second radiotechnology or as a transport system server, for example a ITS server.The entity may be also connectable to the cellular network and may beaccordingly embodied as a V2V communication device or a sensor. Theentity may comprise corresponding program code stored, for example, in amemory of the entity and/or corresponding hardware structure, forexample one or more interfaces, one or more processors, and/or a memory.The entity may implement a transport system application or function.

Referring to FIG. 1, a communication scenario in accordance with anembodiment of the invention will be described in more detail. Acorresponding communication system 100 comprises a radio access network102 and a core network 104, both of which forming a cellular network.

The radio access network 102 comprises one or more access nodes 106a-106 c. For example, the radio access network 102 uses LTE as radiotechnology for communication, and the access nodes 106 a-106 c areaccordingly embodied as eNodeBs. Alternatively, the radio access network102 may be embodied as GERAN with the access nodes 106 a-106 c beingembodied as Base Stations (BS) and/or Base Transceiver Stations (BTS).Alternatively, the radio access network 102 may also be adapted as UTRANwith the access nodes 106 a-106 c being embodied as NodeBs and/or RadioNetwork Controllers (RNC). Further, each access node 106 a-106 c servesone or more cells 108 and may manage a radio resource allocation in theradio access network 102 depending on the particular embodiment of theaccess node 106 a-106 c. In the described embodiment, each eNodeB 106a-106 c serves three cells 108 a-108 c, 108 d-108 f, 108 g-108 i. Theserved cells 108 a-108 c, 108 d-108 f and 108 g-108 i correspond each toa respective individual coverage area of each eNodeB 106 a-106 c forwhich a distribution scheme associated with a control of V2Vcommunication in the communication system 100 is defined. One or moresensors 109 a, 109 b are permanently installed in a ground in amesh-like arrangement over the radio access network 102. For ease ofillustration, only two sensor 109 a, 109 are displayed in FIG. 1.

The core network 104 comprises one or more control nodes 110 a, 110 band/or one or more transport system servers 112 a, 122 b. In thedescribed embodiment, the core network 104 comprises a packet switcheddomain being embodied as Evolved Packet Core (EPC) and comprisingcontrol nodes 110 a, 110 b in the form of Mobility Management Entities(MMES). The transport system servers 112 a, 112 b may be distributed ina cloud over the core network 104 or may form independent networkentities. Additionally or alternatively, the core network 104 maycomprise a circuit switched domain which may comprise one or morecontrol nodes in the form of Mobile Switching Center (MSC) servers.

Vehicles 114 a-114 c for passenger and/or cargo transport are moving ina coverage area of the radio access network 102. The vehicle 114 a is anemergency vehicle, while the vehicles 114 a, 114 c are embodied asvehicles owned by private persons. Each vehicle 114 a-114 c comprisesone V2V communication device 116 a-116 c adapted to operate inaccordance with a first radio technology for performing V2Vcommunication, which radio technology may, for example, may operateaccording to the IEEE 802.11p standard. Transmitted V2V communicationmessages are CAMs. Further, the V2V communication devices 116 a-116 care adapted to operate in accordance with a different second radiotechnology offered by the radio access network 102, namely LTE. Thecommunication system 100 may form an ITS system, and the transportservers 112 a, 112 b may be ITS servers.

Referring to FIG. 2, a method usable in association with controlling V2Vcommunication according to an embodiment of the invention will beexplained. An underlying communication system 100 corresponds to thecommunication system 100 illustrated in FIG. 1.

In a first step 220 of the method, the V2V communication device 116 aprovides information relating to a priority of the V2V communicationmessages to be transmitted, a required transmission area for the V2Vcommunication messages and its own capabilities for transmission via thefirst radio technology. The identified priority of the V2V communicationmessages corresponds to high and is defined in accordance with a vehicleattribute of the vehicle 114 a, for example an attribute indicating thevehicle 114 a being an emergency vehicle. The required transmission areamay correspond to the cells 108 a-108 c, and the information relating tothe priority of the V2V communication messages and the requiredtransmission area may be provided from a transport system application ofthe V2V communication device 116 a, for example a ITS application,towards a radio interface of the V2V communication device 116 a. Theinformation relating to its own transmission capabilities may beprovided from its one or more processors to its radio interface. In anext step 222, the provided information is transmitted to the accessnode 106 a in the same, in two or separate messages via the second radiotechnology.

Thereupon, the V2V communication device 116 b provides in a next step224 information relating to its own transmission capabilities fortransmission via the first radio technology, for example from its one ormore processors towards its radio interface. In a next step 226, the V2Vcommunication device 116 b transmits the provided information to theaccess node 106 a via the second radio technology.

In a next step 228, a transport system server 112 a of a core network104 of the communication system 100 monitors information relating to anaverage connectivity via fixed infrastructure nodes located in theserved cells 108 a-108 i and operable in accordance with the first radiotechnology for performing the V2V communication. To this end, thetransport system server 112 a receives, for example, periodicallyinformation related to the number of infrastructure nodes from thesensors 109 a, 109 b, which information has been forwarded by the accessnodes 106 a-106 c. The sensors 109 a, 109 b in turn have monitoredavailable traffic via the first radio technology in the particularserved area of the cells 108 a-108 i. The transport system server 112 athen calculates the average connectivity in the coverage area 108 a-108c. Further, the transport system server 112 a transmits in a subsequentstep 230 the respective information to the access node 106 a via itsnetwork interface over a core network link between the access node 106 aand the transport system server 112 a.

It is noted that a sequence of the steps 220, 222, the steps 224, 226and/or the steps 228, 230 can be different from the above describedembodiment.

In a next step 232, the access node 106 a monitors information relatingto a priority of the V2V communication messages to be transmitted,information relating to a required transmission area for these V2Vcommunication messages, information relating to capabilities fortransmission via a particular radio technology in its serving area 108a-108 c at a current time and information relating to its own availabletransmission capacity for the V2V communication via the LTE radiotechnology in its serving area 108 a-108 c at this particular time. Tothis end, the access node 106 a uses its radio interface and its networkinterface towards the transport system server 112 a.

Thereupon, in a next step 234, the access node 106 a determines adistribution scheme for distributing a transmission of V2V communicationmessages among the radio technology for performing the V2V communicationand the LTE radio technology. To this end, the access node 106 a usesall monitored information and evaluates a best effort distributionscheme in view of available resource capacities of the access node 106a, costs and reliability for transmission of the V2V communicationmessages via the first and second radio technologies and averageconnectivity via the first and second radio technologies.

During the determination of the distribution scheme, the access node 106a determines the available transmission capacity via the second radiotechnology by monitoring its used capacity in terms of already allocatedresources for a data transmission different from the V2V communicationmessages and its free capacity not being used for communication in termsof its not allocated resources, and accordingly determines its availabletransmission capacity for the V2V communication via the second radiotechnology.

The determination further comprises a determination of a total averageconnectivity via the first radio technology in the cells 108 a-108 c atthe current time by means of evaluating an average connectivity providedby the V2V communication devices 116 a-116 c at the current time. Tothis end, a number of the V2V communication devices 116 a, 116 b whohave provided their transmission capabilities in the steps 222, 226 isdetermined, optionally combined with a location of the respective V2Vcommunication device 116 a, 116 b in the cells 108 a-108 c. Informationrelated to the location may have also been determined by the access node106 a or provided by the respective V2V communication device 116 a, 116b. The total average connectivity is then determined by suitablycombining the average connectivity offered by the fixed infrastructurenodes and the average connectivity provided by the V2V communicationdevices 116 a-116 d in the served cells 108 a-108 c.

In the determination of the distribution scheme, the V2V communicationmessages having the high priority indicated by the V2V communicationdevice 116 a are given precedence over other V2V communication messagesbeing free of an assigned priority and/or having a lower priority.

The determined distribution scheme specifies that all V2V communicationmessages are to be transmitted via the first radio technology forperforming the V2V communication, wherein a subset of these V2Vcommunication messages is to be transmitted via the second LTE radiotechnology. The subsets of the V2V communication messages are selectedbased on its priority, and those V2V communication messages having ahigh priority are part of the subset. The subset of these V2Vcommunication messages are to be transmitted in accordance with atransmission rate of 1/10, if enough V2V communication messages having ahigh priority are to be transmittable in the V2V communication device116 a, 116 b, and else no transmission rate is applied to the subset ofV2V communication messages.

In a next step 236 a, 236 b the access node 106 a broadcasts thedetermined distribution scheme to all V2V communication devices 116 a,116 b being currently located in its serving area 106 a-106 c via thesecond radio technology. In a next step 238, 240, the respective V2Vcommunication device 116 a, 116 b controls the transmission of V2Vcommunication messages to be transmitted in accordance with thedistribution scheme by implementing the distribution scheme in therespective V2V communication device 116 a, 116 b. In a subsequent step242, 244, the respective V2V communication device 116 a, 116 b transmitsthe V2V communication messages using the radio technology for performingthe V2V communication and the LTE radio technology based on the step238, 240 of controlling.

Instead of distributing the distribution scheme in the steps 236 a, 236b via broadcasting, the distribution scheme can be transmitted to therespective V2V communication device 116 a, 116 b via the second radiotechnology in a handover command upon the V2V communication device 116a, 116 b entering the serving area 108 a-108 c of the access node 106 a.Assuming the V2V communication device 116 a to enter the coverage areaformed by the cells 108 a-108 c, the V2V communication device 116 amight not be considered in the distribution scheme received in thehandover command but may be considered in future determined distributionschemes distributed to other V2V communication devices 116 a, 116 b.

Further, the step 234 may be performed by the transport system sever 112a which may accordingly receive the described information required forthe determination of the distribution scheme from the V2V communicationdevices 116 a, 116 b, particularly via the access nodes 106 a-106 c, andfrom the access node 106 a. The determined distribution scheme may bethen transmitted over the core network link to one or more access nodes106 a-106, which in turn broadcast the distribution scheme to the V2Vcommunication devices 116 a-116 c using the second radio technology.

Referring to FIG. 3, a method for controlling V2V communicationaccording to another embodiment of the invention will be explained. Anunderlying communication system 100 associated with the methodcorresponds to the communication system 100 illustrated in FIG. 1.

In a first step 320 of the method, the V2V communication device 116 aprovides its transmission capabilities, for example from its memory toits one or more processors. Thereupon, a step 224 explained withreference to FIG. 2 is performed by the V2V communication device 116 b.In a next step 326, the provided information is transmitted from the V2Vcommunication device 116 b to the V2V communication device 116 a via thefirst radio technology. In a step 348, a transport system server 112 aof a core network 104 of the communication system 100 providesinformation relating to a priority of the V2V communication messages tobe transmitted in the coverage area 108 a-108 c served by the accessnode 106 a. A first high priority is assigned to all V2V communicationmessages in which the geographical location of the respectivetransmitting V2V communication device 116 a-116 c is in the cell 108 a.A second lower priority is assigned to all V2V communication messages inwhich the geographical location of a respective transmitting V2Vcommunication device 116 a-116 c is in the cells 108 b, 108 c. In a nextstep 330, the provided information is transmitted from the transportsystem server 112 a to the V2V communication device 116 a via a corenetwork link and the second radio technology.

Thereupon, a step 332 is performed during which information relating toan available free capacity for the V2V communication via the secondradio technology, hence the radio technology of the radio access network102 is monitored. The monitored information is transmitted in a nextstep 346 from the access node 106 a to the V2V communication device 116a using the second radio technology.

It is noted that a sequence of the step 320, the steps 224, 326, thesteps 232, 346 and/or the steps 348, 330 may differ from the abovedescribed embodiment.

In a next step 334, the V2V communication device 116 a determines thedistribution scheme to be used in the coverage area 108 a-108 c of theaccess node 106 a using the information received in the steps 326, 330and 346. The determined distribution scheme specifies that all V2Vcommunication messages having the first priority are to be transmittedvia the radio technology of the radio access network 102, while all V2Vcommunication messages having the second priority are to be transmittedvia the radio technology for performing the V2V communication.Thereupon, a step 238 explained with reference to FIG. 2 is performed bythe V2V communication device 116 a in terms of implementing thedetermined distribution scheme in a memory of the V2V communicationdevice 116 a and using the distributing scheme when controlling atransmission of V2V communication messages.

In a next step 336, the V2V communication device 116 a transmits thedistribution scheme 336 to the V2V communication device 116 b in a V2Vcommunication message using the first radio technology for performingthe V2V communication. The distribution scheme may be included in aregularly transmitted V2V communication message or in a separate V2Vcommunication message which may be transmitted when having determinedthe distribution scheme. Thereupon, in a step 240, the V2V communicationdevice 116 b, upon receipt of the distribution scheme, controls itstransmission of V2V communication messages to be transmitted inaccordance with the received distribution scheme. To this end, the V2Vcommunication device 116 b implements the distribution scheme in itsmemory. Thereupon, steps 242, 244 explained with reference to FIG. 2 areperformed by the respective V2V communication device 116 a, 116 b.

FIG. 4 illustrates an exemplary implementation of a V2V communicationdevice 416. The V2V communication device 416 may correspond to the V2Vcommunication device 116 a, 116 b, 116 c described with reference toFIGS. 1 to 3. The V2V communication device 416 may be mounted on board avehicle, for example a road vehicle for passenger and/or cargotransport.

The V2V communication device 416 is adapted to control V2Vcommunication. The V2V communication is performable using a first radiotechnology for performing the V2V communication and a second radiotechnology for accessing a cellular network. The V2V communicationdevice 416 is adapted to control a transmission of V2V communicationmessages in accordance with a determined distribution scheme fordistributing a transmission of the V2V messages among the first radiotechnology and the second radio technology. The V2V communication device416 may be also adapted to perform a method described above.

For example, the V2V communication device 416 comprises a first radiointerface 450 for the V2V communication via the first radio technology.A second radio interface 452 of the V2V communication device 416 isadapted to operate in accordance with a radio technology for accessingthe cellular network. One or more processors 454 of the V2Vcommunication device 416 are coupled to the first radio interface 450and the second radio interface 452. The one or more processors 454 arefurther coupled to a memory 456 of the V2V communication device 416. Thememory 456 may include a Read-Only Memory (ROM), for example a FlashROM, a Random-Access Memory (RAM), for example a Dynamic RAM (DRAM) orStatic RAM (SRAM), a mass storage, for example a hard disk or asolid-state disk, or the like.

The memory 456 includes or stores suitable configured program code to beexecuted by the one or more processors 454, in order to implement theabove-described functionalities of the V2V communication device 416. Tothis end, the program code in the memory 456 comprises a control module458 implementing the functionalities for controlling the transmission ofthe V2V communication messages to be transmitted in accordance with thedetermined distribution scheme. The program code in the memory 456 mayfurther comprise a determination module 460 for implementingfunctionalities relating to determining the distribution scheme. Furtherprogram code in the memory 456 includes a providing module 462 which mayimplement functionalities for providing information impacting adetermination of the distribution scheme. A transport system applicationmodule 464 of the program code in the memory 456 may implementfunctionalities of a transport system application, for example an ITSapplication, for operating the V2V communication device 416 inaccordance with a transport system, for example ITS. The program code inthe memory 456 may further comprise a receiving module 466 forimplementing functionalities for receiving information related to thecontrol of V2V communication. A transmission module 468 of the programcode of the memory 456 may implement functionalities for transmittinginformation related to controlling V2V communication, for example theinformation provided by means of the providing module 462 or adetermined distribution scheme.

For example, the transport system application module 464 may implementfunctionalities for determining a priority of V2V communicationmessages, for example from a vehicle attribute included in the V2Vcommunication messages. The providing module 462 may provideinformation, for example a priority of the V2V communication messages tobe transmitted, from the transport system application to the at leastone processor 454 and/or the first or second interface 450, 452. Theproviding module 462 may be also implement functionalities related tomonitoring information. The control module 458 may further implementfunctionalities for implementing known control functionalities of a V2Vcommunication device 416. The determination module 460 may alsoimplement functionalities for determining the priority of the V2Vcommunication messages to be transmitted when applying the distributionscheme.

According to another embodiment of the invention, a computer program maybe provided. The computer program may comprise or may be embodied in atleast one of the above mentioned modules 458-468 of the program code.The computer program is executable by the one or more processors 454 andmay cause the V2V communication device 416 to perform an above describedmethod. The computer program may be provided in a downloadable form ormay be stored on a computer program product, for example a disk.

FIG. 5 illustrates an exemplary implementation of a node 569. The node569 may correspond to the access node 106 a-106 c described withreference to FIGS. 1 to 3. Alternatively, the node 569 may correspond tothe transport system server 112 a being adapted to determine thedistribution scheme, as described with reference to FIG. 2.

The node 569 is adapted for a cellular network, for example is part ofthe cellular network, and is usable in association with controlling V2Vcommunication. The V2V communication is performable using a first radiotechnology for performing the V2V communication and a second radiotechnology for accessing the cellular network. The node 569 is adaptedto determine a distribution scheme for distributing a transmission ofV2V communication messages among the first radio technology and thesecond radio technology, and to transmit the determined distributionscheme to a V2V communication device. The node 569 is adapted to performa method described above.

For example, the node 569 comprises a network interface 552 adapted tooperate in accordance with the second radio technology for accessing thecellular network and/or for communication with further nodes, forexample of a core network, of the cellular network. In a case in whichthe node 569 may be embodied as an access node, the interface mayimplement a radio interface and a network interface towards a corenetwork. In a case in which the node 569 may be embodied as a transportsystem server, the interface 562 may be embodied as a network interfacetowards the core network and/or in accordance with the second radiotechnology. One or more processors 554 of the node 569 are coupled tothe interface 552. The one or more processors 554 are further coupled toa memory 556 of the node 569. The memory 556 may include a Read-OnlyMemory (ROM), for example a Flash ROM, a Random-Access Memory (RAM), forexample a Dynamic RAM (DRAM) or Static RAM (SRAM), a mass storage, forexample a hard disk or a solid-state disk, or the like.

The memory 556 includes or stores suitable configured program code to beexecuted by the one or more processors 554, in order to implement theabove-described functionalities of the node 569. To this end, theprogram code in the memory 556 may comprise a control module 558implementing known control functionalities of a node 569. The programcode in the memory 556 may further comprise a determination module 560for implementing functionalities relating to determining thedistribution scheme. A providing module 562 of the program code in thememory 556 may implement functionalities for providing informationimpacting a determination of the distribution scheme to be used by theone or more processors 556 when executing the determination module 560.A transport system function module 564 of the program code in the memory556 may implement functionalities of a transport system function, forexample an ITS function, for operating the node 569 in accordance with atransport system, for example ITS. The memory 556 may further comprise aprogram code in the form of a receiving module 566 for implementingfunctionalities for receiving information related to the control of V2Vcommunication, for example information impacting the determination ofthe distribution scheme. A transmission module 568 of the program codein the memory 556 may implement functionalities for transmittinginformation related to controlling V2V communication, for example thedetermined distributing scheme and/or the information impacting thedetermination of the distribution scheme.

For example, the providing module 562 may implement functionalitiesrelated to monitoring information impacting the determination of thedistribution scheme. The transport system function module 568 mayimplement functionalities for defining a priority of V2V communicationmessages, for example based on a vehicle attribute to be included in aV2V communication message. The providing module 562 may provideinformation, for example information relating to an available networkcapacity, from the first and/or second in the one or more processors554.

According to another embodiment of the invention, a computer program maybe provided. The computer program may comprise or may be embodied in atleast one of the above mentioned modules 558-568. The computer programis executable by the one or more processors 554 and may cause the node569 to perform the above described methods. The computer program may beprovided in a downloadable form or may be stored on a computer programproduct, for example a disk.

FIG. 6 illustrates an exemplary implementation of an entity 672. Theentity 672 may correspond to the access node 106 a described withreference to FIGS. 1, 3. Alternatively, the entity 672 may correspond tothe transport system server 112 a described with reference to FIGS. 1, 2which may optionally be adapted to determine the distribution scheme, asdescribed in FIGS. 1, 2. Further, the entity 672 may correspond to theV2V communication device 116 a described with reference to FIGS. 1, 2 orto the V2V communication device 116 b described with reference to FIGS.1 to 3. Further, the entity 692 may also correspond to the sensor 109 a,109 b described with reference to FIGS. 1, 2

The entity 672 is usable in association with controlling V2Vcommunication. The V2V communication is performable using a first radiotechnology for performing the V2V communication and a second radiotechnology for accessing the cellular network. The entity 672 is adaptedto transmit information impacting a determination of a distributionscheme for distributing a transmission of V2V communication messagesamong the first radio technology and the second radio technology to afurther entity, particularly a V2V communication device adapted todetermine the distribution scheme, or a node of the cellular networkadapted to determine the distribution scheme. The entity 672 may be alsoadapted to perform a method as described above.

For example, the entity 672 comprises a first interface 650 for the V2Vcommunication via the first radio technology and/or a second interface652 which is adapted to operate in accordance with a radio technologyfor accessing the cellular network and/or for communication with furthernodes, for example of a core network, of the cellular network. If theentity 672 may be embodied as a V2V communication device, the firstinterface 650 may be embodied as a radio interface for V2V communicationand the second interface 652 may be embodied as a second radio interfaceoperable in accordance with the second radio technology. If the entity672 is embodied as an access node, one radio interface may be providedwhich may operate in accordance with the second radio technology and forcommunication with further nodes, for example of a core network. If theentity 672 may be embodied as a transport system server, the interface650 may be embodied as a network interface towards further nodes, forexample of the core network, and/or in accordance with the second radiotechnology. If the entity 672 may be embodied as a sensor, the firstradio interface may operate in accordance with the first radiotechnology and the second interface may be embodied as a radio interfacein accordance with the second radio technology. The sensor may compriseonly one of the latter interfaces 650, 652. One or more processors 654of the entity 672 are coupled to the first interface 650 and/or thesecond interface 652, depending on the embodiment. The one or moreprocessors 654 are further coupled to a memory 656 of the entity 672.The memory 656 may include a Read-Only Memory (ROM), for example a FlashROM, a Random-Access Memory (RAM), for example a Dynamic RAM (DRAM) orStatic RAM (SRAM), a mass storage, for example a hard disk or asolid-state disk, or the like.

The memory 656 includes or stores suitable configured program code to beexecuted by the one or more processors 654, in order to implement theabove-described functionalities of the entity 672. To this end, theprogram code in the memory 656 may comprise a control module 658implementing known control functionalities of the entity 672. Aproviding module 662 of the program code in the memory 656 may implementfunctionalities for providing information impacting a determination ofthe distribution scheme. An optional transport system application orfunction module 664 of the program code in the memory 656 may implementfunctionalities of a transport system application or function, forexample, an ITS application or ITS function, for operating the entity672 in accordance with a transport system, for example ITS. The programcode in the memory 656 may further comprise a receiving module 666 forimplementing functionalities for receiving information related to thecontrol of V2V communication. A transmission module 668 of the programcode in the memory 656 may implement functionalities for transmittinginformation related to controlling V2V communication, for example theinformation impacting the determination of the distribution scheme.

For example, the providing module 662 may implement functionalitiesrelated to monitoring the information impacting the determination of thedistribution scheme. The providing module 662 may further provide theinformation, for example, from the transport system application orfunction to the one or more processors 654 and and/or to the firstand/or second interface 650, 652 for further transmission thereof to aV2V communication device adapted to determine the distribution scheme orto the node adapted to determine the distribution scheme. The transportsystem application or function module 668 may implement functionalitiesfor determining or identifying a priority of V2V communication messages,for example from a vehicle attribute included in the V2V communicationmessages.

According to another embodiment of the invention, a computer program maybe provided. The computer program may comprise or may be embodied in atleast one of the above mentioned modules 658-668. The computer programis executable by the one or more processors 654 and may cause the entity672 to perform the above described methods. The computer program may beprovided in a downloadable form or may be stored on a computer programproduct.

Modifications and other embodiments of the disclosed invention will cometo mind to one skilled in the art having the benefit of the teachingspresented in the foregoing descriptions and the associated drawings.Therefore, it is to be understood that the embodiments are not to belimited to the specific embodiments disclosed and that modifications andother embodiments are intended to be included within the scope of thisdisclosure. Although specific terms may be employed herein, they areused in a generic and descriptive sense only and not for purposes oflimitation. The description of the invention with reference to 3GPP maynot exclude the described invention being applicable in othercommunication networks and/or technologies, these networks and/ortechnologies being different from 3GPP.

1. A method for controlling vehicle-to-vehicle communication, the methodcomprising: determining a distribution scheme for distributing atransmission of vehicle-to-vehicle communication messages among a firstradio technology and a second radio technology for accessing a cellularnetwork, and a vehicle-to-vehicle communication device controlling thetransmission of the vehicle-to-vehicle communication messages inaccordance with the identified distribution scheme.
 2. The method ofclaim 1, wherein the determined distribution scheme specifies atransmission rate in accordance with which the vehicle-to-vehiclecommunication messages are to be transmitted via the first and/or secondradio technologies.
 3. The method of claim 1, wherein the determineddistribution scheme specifies a transmission frequency in accordancewith which vehicle-to-vehicle communication messages are to betransmitted via the first and/or second radio technologies.
 4. Themethod of claim 1, wherein the determined distribution scheme specifiesthat all vehicle-to-vehicle communication messages are to be transmittedvia the first radio technology and a subset of the vehicle-to-vehiclecommunication messages are to be transmitted via the second radiotechnology.
 5. The method of claim 1, wherein the determineddistribution scheme specifies that a vehicle-to-vehicle communicationmessage having a certain priority is to be transmitted via the secondradio technology, wherein a vehicle-to-vehicle communication messagehaving a priority different from the certain priority is to betransmitted via the first radio technology.
 6. The method of claim 1,wherein the priority of a vehicle-to-vehicle communication message isdefined based on a content of the vehicle-to-vehicle communicationmessage.
 7. The method of claim 1, wherein the distribution scheme isdetermined for a certain coverage area of the second radio technology.8. The method of claim 1, wherein the distribution scheme is determinedby a vehicle-to-vehicle communication device or by a node of thecellular network, particularly an access node operating in accordancewith the second radio technology or a transport system server.
 9. Themethod of claim 1, the method further comprising: transmitting thedetermined distribution scheme to the vehicle-to-vehicle communicationdevice in a broadcast transmission or in an unicast transmission. 10.The method of claim 9, wherein the determined distribution scheme istransmitted in a handover command to the vehicle-to-vehiclecommunication device when the vehicle-to-vehicle communication deviceenters a coverage area of the second radio technology for which thedistribution scheme has been determined.
 11. The method of claim 1,wherein the distribution scheme is determined based on at least oneinformation selected from a group of information comprising informationrelating to a density of entities comprising transmission capabilitiesfor transmission via the first radio access technology in a certaincoverage area of the second radio technology at a given time,information relating to an average connectivity via the first radiotechnology in a certain coverage area of the second radio technology ata given time, information relating to an available transmission capacityto be usable for the V2V communication via the second radio technologyin a certain coverage area of the second radio technology at a giventime, information relating to a priority and/or a type of avehicle-to-vehicle communication message to be transmitted, andinformation relating to a required transmission area in which avehicle-to-vehicle communication message is to be transmitted.
 12. Themethod of claim 9, wherein the at least one information is provided byan entity, particularly the vehicle-to-vehicle communication device, afurther vehicle-to-vehicle communication device, the node or a sensor.13. (canceled)
 14. A vehicle-to-vehicle communication device forcontrolling vehicle-to-vehicle communication, the vehicle-to-vehiclecommunication device being adapted to: obtaining information identifyinga selected distribution scheme for distributing a transmission ofvehicle-to-vehicle communication messages among a first radio technologyand a second radio technology for accessing a cellular network; andcontrol a transmission of vehicle-to-vehicle communication messages inaccordance with the identified distribution scheme.
 15. (canceled)
 16. Avehicle comprising a vehicle-to-vehicle communication device accordingto claim
 14. 17. A method usable in association with controllingvehicle-to-vehicle communication, the method being performed by a nodeof the cellular network and comprising: determining a distributionscheme for distributing a transmission of vehicle-to-vehiclecommunication messages among a first radio technology and a second radiotechnology for accessing a cellular network, and transmittinginformation is the determined distribution scheme to avehicle-to-vehicle communication device.
 18. A node in a cellularnetwork for controlling vehicle-to-vehicle communication, the node beingadapted to: determine a distribution scheme for distributing atransmission of vehicle-to-vehicle communication messages among a firstradio technology and a second radio technology for accessing a cellularnetwork, and transmit information identifying the determineddistribution scheme to a vehicle-to-vehicle communication device. 19.(canceled)
 20. The node of claim 18, adapted as an access node beingadapted to operate in accordance with the second radio technology or asa transport system server. 21.-27. (canceled)
 28. The method of claim 1,wherein the vehicle-to-vehicle communication device performs thedetermining step.
 29. The method of claim 1, wherein the determiningstep consists of the vehicle-to-vehicle communication receivinginformation identifying the distribution scheme.